The anticoagulant activity of heparin was first reported by Howell et al. [Am. J. Physiol., 47, 328 (1918-19)]. The investigations carried out by Chargaff et al. [J. Biol. Chem. 115, 155 (1936)] on other natural and synthetic macromolecules with heparin-like activity revealed that the anticoagulant macromolecules always contain sulfate groups (e.g. heparin or potassium salt of the acidic sulfuric acid ester of polyvinylalcohol, prepared by said authors) but not all polymers containing sulfate groups show anticoagulant activity.
According to later publications, in contrast to the findings of Chargaff et al., there are described polymers which are potent anticoagulants, though they fail to contain sulfate groups [e.g. R. Machovich and I. Horvath: Thrombos. Res. 11, 765 (1977) and U.S. Pat. No. 3,844,989].
Until now the role of the sulfate groups has not unambiguously been made clear, and there is no polymer on the market which can satisfactorily replace the organogenic heparin having a varying composition.